val get: string -> string
val set: key:string -> value:string -> unit
+ (** remove a key from the current environment, next get over this key will
+ * raise Key_not_found until the key will be redefined *)
+val unset: string -> unit
+
(** {2 Typed interface}
* Three basic types are supported: strings, int and strings list. Strings
* correspond literally to what is written inside double quotes; int to the
* parsing of an integer number from ; strings list to the splitting at blanks
* of it (heading and trailing blanks are removed before splitting) *)
-val get_string: string -> string (* alias for bare "get" above *)
-val get_int: string -> int
-val get_float: string -> float
-val get_string_list: string -> string list
+val get_string: string -> string (* alias for bare "get" above *)
+val get_int: string -> int
+val get_float: string -> float
+val get_bool: string -> bool
+val get_string_list: string -> string list
(* alias for bare "set" above *)
-val set_string: key:string -> value:string -> unit
-val set_int: key:string -> value:int -> unit
-val set_float: key:string -> value:float -> unit
-val set_string_list: key:string -> value:string list -> unit
+val set_string: key:string -> value:string -> unit
+val set_int: key:string -> value:int -> unit
+val set_float: key:string -> value:float -> unit
+val set_bool: key:string -> value:bool -> unit
+val set_string_list: key:string -> value:string list -> unit
+
+(** {3 Optional values interface}
+ * Functions below took as first argument respectively a "getter" and a "setter"
+ * function. A getter is one of the get_* function above, a setter is one of the
+ * set_* function above. Returned value is a get (set) function typed as the
+ * given getter (setter) whith optional values. None is returned for missing
+ * keys and None can be assigned to a key removing it from the registry.
+ *)
+
+val get_opt:
+ (string -> 'a) (* getter *) ->
+ string -> 'a option
+val set_opt:
+ (key:string -> value:'a -> unit) (* setter *) ->
+ key:string -> value:'a option -> unit
(** {2 Validators}
* Each key may have zero or more associated validators, that are predicates